In the course of medical care, healthcare providers often have to place an endotracheal tube into a person's airway. This process, intubation, may be necessary for artificial ventilation, protecting the airway from aspiration of stomach contents or for the delivery of anesthetics. Intubation may be performed by paramedics or military personnel in the field, in emergency departments, hospitals or in the operating room.
An endotracheal tube 34 is shown in FIG. 1. An endotracheal tube has a tubular shaft 17 with a distal end 14, a proximal end 15, an inflatable cuff 12 and an inflation lumen 10. During intubation the distal end 14 of the endotracheal tube is inserted into a person's mouth and slidably positioned into the person's trachea such that proximal end 15 projects outward from person's mouth. Inflatable cuff 12 is then used to secure the endotracheal tube 34 in the trachea. Inflatable cuff 12 is inflated by supplying air at inflation lumen 10. Oxygen and/or anesthetics are then supplied to the person by supplying them utilizing proximal end 15 of endotracheal tube 34.
In many situations a person's glottis is not visible to the physician such as when obstructed by blood, secretions, swelling, abnormal anatomy, or when person is obese. This is termed the “difficult airway” and in these situations proper intubation may be difficult and ventilation of the person may fail if endotracheal tube 34 of FIG. 1 is incorrectly inserted into the person's esophagus rather than the person's trachea. To facilitate proper intubation, a variety of introducers are utilized.
FIG. 2 is a drawing of a standard stylet 30. To facilitate intubation of the person, a plastic coated metal stylet is frequently used to stiffen endotracheal tube 34 of FIG. 1 by inserting standard stylet 30 within the endotracheal tube. A distal end 24 of standard stylet 30 is inserted into the endotracheal tube such that a proximal end 20 of the standard stylet 30 extends outward from proximal end 15 of endotracheal tube 34 of FIG. 1. The standard stylet 30, together with the endotracheal tube can then be bent to form a shape that facilitates insertion into the trachea of a person.
FIG. 3 shows a standard stylet 30 placed within an endotracheal tube 34 and disposed within a person's airway. The distal end of the endotracheal tube is disposed within a person's trachea 32. Once an endotracheal tube 34 containing standard stylet 30 is properly positioned as indicated in FIG. 3, standard stylet 30 is then removed leaving endotracheal tube 34 disposed in the trachea. A source of oxygen can then be coupled to the proximal end of endotracheal tube 34.
Since visibility is often partially or fully obstructed in the case of a difficult airway, intubation utilizing a standard stylet is not optimal. The distal end 14 of endotracheal tube 34 of FIG. 1 is many millimeters in diameter and decreases the operator's visibility of the airway. The large diameter of endotracheal tube 34 makes it difficult to slip under the epiglottis such to access to the trachea. Therefore, since visibility is not optimal and since the relatively large diameter of the endotracheal tube further frustrates intubation, other devices or introducers are often utilized in the difficult airway situation.
One of these introducers is shown in FIG. 4, a drawing of a gum elastic bougie 40 or “bougie.” The bougie 40 is used in combination with a laryngoscope to first locate a person's epiglottis or vocal cords and then as a guide for insertion of the endotracheal tube.
The bougie 40 is approximately 70 centimeters long and includes a distal end 44 and a proximal end 42. Both the proximal end 42 and distal end 44 are rounded such for prevention of trauma to the person during insertion of bougie 40 into the airway. Commercially supplied bougies are marketed and sold in varying diameters, and some are approximately 5 millimeters in diameter. This relatively small diameter of the bougie compared to the diameter of an endotracheal tube increases the possibility of proper insertion since it fits into smaller openings and allows for increase visibility during intubation. However, the bougie is approximately 70 centimeters in length and is cumbersome and is also not immediately disposed to operator's use.
FIG. 5 shows a bougie 40 disposed within a person's airway. When bougie 40 is correctly guided into the airway, distal end 44 will enter a person's trachea 32. The trachea 32 is composed of C-shaped cartilaginous rings known as tracheal rings 39. An esophagus 57 is devoid of tracheal rings and is shown in FIG. 5 adjacent trachea 32. During intubation, distal end 44 of bougie 40 glides over tracheal rings 39 and the physician or operator will feel a vibration or tapping sensation at a proximal end 42. This is known as “tracheal clicking.” The operator is then assured that bougie 40 is correctly located in the airway and not in the person's esophagus. If tracheal clicking is not felt at proximal end 42, bougie 40 is likely disposed within esophagus 57 and must be withdrawn and replaced.
Bougie 40 finds use in the difficult airway situation since it is smaller in diameter than the endotracheal tube and allows for greater operator visibility and since distal end 44 is easier to slip under the epiglottis and into the airway when compared to the endotracheal tube. Bougie 40 is also manufactured with an angled or “Coude tip” which facilitates tracheal clicking as a result of improved contact with tracheal rings 39.
Once the bougie has been correctly placed within the person's trachea, endotracheal tube 34 can be inserted over the proximal end 42 of bougie 40 and slidably positioned into the person's trachea using bougie 40 as a guide. Bougie 40 is then slidably removed from the person leaving endotracheal tube 34 disposed within the trachea for ventilation or delivery of anesthetics. Although a bougie may offer improved performance over the standard stylet, there remains a need for improved visibility and bougie 40 is also prone to twisting during use making proper handling less than ideal.
Another introducer, a lightwand 60, is shown in FIG. 6. The lightwand has a handle 52 located at the proximal end of a shaft 54 and a light source 56 located at the distal end of shaft 54. A switch 58 disposed on handle 52 of lightwand 60 and allows the operator to control light source 56.
To intubate a person using a lightwand, an endotracheal tube is slipped over the light source 56 at the distal end of shaft 54 and is positioned on shaft 54 between handle 52 and light source 56. A bend is then placed at the distal portion of the light wand such that the distal end containing light source 56 is at an approximate 90 degree angle relative to the axis of shaft 54. The light source is then switched on using switch 58 and the distal portion of the lightwand is then inserted into person's throat and advanced until an external glow is seen emanating from the person's suprasternal notch. This glow is externally visible to the operator and indicates that the lightwand is properly positioned in the trachea of a person. If a glow is not seen than the lightwand is incorrectly positioned in person's esophagus and must be withdrawn and reinserted until proper placement is achieved.
FIG. 7 shows a lightwand 60 and an endotracheal tube 34 disposed within a person's trachea. A light source 56 is viewable externally when lightwand 60 is properly positioned in the airway as shown. If lightwand 60 were incorrectly positioned within an esophagus 57, light source 56 would not be externally visible. Lightwand 60 is smaller than other introducers such as a bougie and can easily store in situations where space is limited such as a field kit or portable airway bag. However lightwand 60 is not adaptable to standard orotracheal techniques since it calls for the use of a guide or a metal stylet that is removable such to prevent trauma. Additionally, lightwands do not produce the tracheal clicking as evidence of proper intubation thus depriving the operator of an effective manner of validating proper placement.
In a trauma situation, the aforementioned introducers and similar commercially available devices are problematic since they are either quite lengthy, cumbersome or not readily adaptable to standard orotracheal techniques. In addition, where one introducer may have been initially selected to intubate a person, if physician subsequently desires a different introducer, he will waste precious time as he must remove the introducer that was initially selected and replace it with the more desirable alternative. An optimal introducer is thus desired which eliminates the combined disadvantages of the aforementioned introducers.